1. Field of the Invention
This invention relates to magnetohydrodynamic methods and apparatus for converting radiative electromagnetic signals as energy, such as non-coherent, coherent, and particle beam radiation, into electrical energy.
2. The Nature of Magnetohydrodynamic Effect
A magnetohydrodynamic generator is an apparatus for generating electrical power from the kinetic energy of charged particles in a flowing conductive fluid. In such a generator, positive and negative charged particles are forced to flow through an MHD electrode system which includes a magnetic field. The magnetic field and the flow direction are perpendicular to a pair of electrodes spaced apart on either side of the flow path. In operation, the magnetic field, in accordance with Faraday's Law, induces an electromotive force in the moving fluid. If suitable electrodes are used to make contact with the moving fluid, and are connected to a load, current will flow in the fluid, and energy is delivered from the fluid to the load.
3. History of the Art
Although scientists have known about the magnetohydrodynamic effect for many years, it has never been heretofore considered a practical method for converting radiative energy to electricity. Instead, the MHD effect has been explored largely as a substitute for conventional generators in converting fossil fuels into electricity. Proposed MHD generators for these applications typically formed charged particles from heating a working fluid, as in conduction heating, and applying an ionizing electrical discharge across the heated fluid.
The shortcomings of these conventional generators are manifold. Such systems typically utilize ionized gas flow at high speeds, often in the supersonic Mach 2 or Mach 5 regions, and they are maintained at high temperatures, often in excess of the melting point of typical structural materials. Moreover, the maintenance and control of electrical discharges in a plasma flowing at supersonic speeds is exceedingly difficult. As a consequence, the plasma generated is not uniform in cross section or in time. Furthermore, these systems generate waste combustion by-products which cannot be recycled within the system and must be disposed of in a non-polluting manner. These shortcomings have prevented MHD electrical power generation from becoming a practical means of electrical power generation.
The foreseeable need is for a new approach to MHD generation which will convert radiative energy into electrical energy without the necessity of intermediate chemical reactions.